RIYADH, Saudi Arabia (CNN) --The large U.S. military presence at Saudi Arabia's Prince Sultan Air Base is expected to end in the coming months, depending on the security situation in Iraq, U.S. officials told CNN on Tuesday.

The decision to move significant U.S. military resources and personnel to neighboring Qatar marks a major shift in U.S. policy in the Persian Gulf region after a longtime presence in Saudi Arabia, currently at about 5,000 troops.

More than 100 aircraft and the U.S. Combined Air Operations Center at the base are expected to make the move, and some of those aircraft could be permanently reassigned to the United States, officials said.

The center will be moved to Al Udeid Air Base in Qatar, part of the post-war U.S. military presence in the Persian Gulf, military sources have told CNN.

However, officials said the United States will maintain a robust military relationship with the Saudis, including a training and exercise program.

During the war in Iraq, Saudi Arabia allowed the United States to use Prince Sultan as a command and control center for U.S. aircraft. U.S. aerial refueling tankers, reconnaissance planes and other noncombat aircraft were allowed to land and take off there, but Saudi Arabia denied the United States permission to use its bases to attack Iraq.

"By transferring the command and control [center] from Saudi Arabia to the air base in Qatar, they will not face the same difficulties they have had in Saudi Arabia in recent years in getting approval for specific operations," said Richard Murphy, a former U.S. ambassador to Saudi Arabia.

In January 2002, White House Chief of Staff Andrew Card told CNN that Saudi officials had asked the United States to reduce its military presence there. "I think it's in the long-term interest of both countries," Card said.

Exiled Saudi Osama bin Laden has cited the presence of U.S. troops in Saudi Arabia as a core grievance in his self-proclaimed holy war against the United States. Fifteen of the 19 September 11 hijackers were from Saudi Arabia, according to the U.S. government.

In addition, anti-American and pro-bin Laden sentiment has been strong in some parts of the kingdom, home of the Islamic holy cities of Mecca and Medina.

The Combined Air Operations Center has been operating from Prince Sultan since 1997, monitoring airspace operations across the region and conducting patrol missions in the former "no-fly" zone over southern Iraq.

The United States helped build military installations in Saudi Arabia during the 1980s and sent hundreds of thousands of troops there during the 1991 Persian Gulf War.